The one exercise that could save your life

BREAKING up prolonged sitting with simple leg exercises every half an hour can lessen the damaged caused by inactivity, in those most at risk of heart disease.

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BREAKING up prolonged sitting with simple leg exercises every half an hour can lessen the damaged caused by inactivity, in those most at risk of heart disease.

The findings add to the growing weight of research that long chunks of unbroken sitting increases the risk of heart disease, type 2 diabetes and some cancers.

But importantly, there is more evidence to show that by getting up and moving regularly -particularly during the most dangerous first two hours of sitting — these risks can be reversed.

Researchers from the Baker Heart and Diabetes Institute took overweight and inactive adults - those at high risk of heart disease — to test whether simple exercises could protect against changes in blood vessels that occur during prolonged sitting.

The adults either sat uninterrupted for five hours, or broke up their sitting every 30 minutes with three minutes of half squats, calf raises or single knee lifts.

Those who sat continuously had impaired vascular function, particularly within the first two hours of sitting, which is associated with the onset of cardiovascular disease. Exercise mitigated these effects. The findings were published in the Journal of Applied Physiology.

“We know that sitting is characterised by muscle inactivity and reduction in blood flow,” said lead researcher Professor David Dunstan.

“Rising from the chair and engaging those large muscles shifts all that. It’s like starting up the body’s engine again.”

Almost two thirds of adults are overweight or obese, and with two million Australians at high risk of developing type 21 diabetes it is the nation’s fastest growing chronic condition.

Prof Dunstan said it was important to look at practical interventions for those at risk of heart disease, given that it killed 80 per cent of people with type 2 diabetes.

“Many believe those two conditions coexist, and given the prevalence of diabetes around the world it’s likely to affect large numbers of the Australian population,” Prof Dunstan said.

“This is starting to provide the rationale for why we would want to be avoiding prolonged, uninterrupted sitting throughout the day.”

The Baker is already testing whether different groups of the population need to break up their sitting in different ways to reap the benefits, with in a number of clinical trials involving people with type 1 and 2 diabetes and Polycystic ovary syndrome underway.

Later this year, the institute will start recruiting for their first interventional study involving patients in the real world, when they enlist 250 adult office workers with type 2 diabetes.

“It appears the processes associated with sitting are most magnified in people who are considered inactive, which is about 60 per cent of the population,” he said.

“It’s difficult to get people up and walking in an open place office because it can be distracting. These activities we chose can be performed on the spot, while you’re looking at the computer screen.”